Mud gun



July 8, 1941. A. 0501.: EI'AL MUD GUN Filed March 26, 1938 2 Sheets-Sheet 1 M W a 0 W W i 5% k F? 0 WE u .Fy A. OSOLIN ETAL MUD GUN Filed March 26, 1938 2 Sheeis-Sheet 2 Qm MR0 [F Patented July 8, 1941 UNITED STATES PATENT OFFICE MUD GUN Alfred Osolin, Shaker Heights, Ohio, and Jay W. Ferree, Swissvale, Pa.

The present invention relates to mud guns and, more particularly, to mud guns for closing furnace tap-holes.

An object of the present invention is to provide an improved mud gun capable of maintaining a constant and steady pressure on the clay or other plastic materials employed to stop the tap-hole.

Another object is to provide a mud gun which is safe and efiicient in operation in that it is not necessary to take the blast 0115 the furnace on which the Work is being ,done, and in that it is impossible for metal to blow back through the gun.

A further object is to provide a gun which will contain suflicient clay to stop the tap-hole without recharging the gun, thus eliminating the necessity of the workmen approaching the furnace while the operation of stopping the hole is in progress.

In the drawings:

Figure 1 is a plan, partially in section, showing a mud gun constructed in accordance with this invention;

Figure 2 is a section taken on the line II-II of Figure 1;

Figure 3 is a section on line III-III of Figure 2;

Figure 4 is a detailed section of the guiding means for rotating the piston during its longitudinal travel;

Figure 5 is a longitudinal section of a modified form for rotating the piston; and, 1

Figure 6 is a section on line VIVI of Figure 5.

The mud gun to which this application is particularly directed comprises a piston or plunger cylinder or gun barrel 2 having a tapered nozzle 3 secured, in any conventional manner, to the forward end of said cylinder or gun barrel and a piston-guide cylinder 4 formed integrally with a gear-housing 5 on which is mounted an electric motor 6. The piston cylinder or gun barrel 2 is provided with an opening I through which the clay or mud is charged into the cylinder or gun barrel. A cover hatch or door 8, of any conventional design, is pivotally secured to said gun barrel to close the opening after the clay or mud has been charged into said gun barrel. A similar opening 9 is provided on the top side of said gun barrel adjacent its forward end through which hard clay or mud may be removed when it is desired to clean out the front end of the gun. A cover hatch or door [0, similar to the door 8, normally closes the opening 9 in said gun barrel.

The piston-guide cylinder 4 is provided with a guide-bar l2 which is fastened to the inner surface of said cylinder 4. The guide-bar I2 is so positioned and arranged as to follow the contour of the cylinder in a spiral direction and extends from the front wall of said gear-housing 5 to the front end of said cylinder 4. The guidebar l2 may be fastened to the cylinder wall in any conventional manner and, while the drawings show the guide-bar l2 following the contour of the cylinder wall half way around its length, it may, if desired, extend one full turn or any number of turns around the cylinder length. An opening I3 is provided through the under side of the wall of said cylinder 4 near the front end thereof whereby any accumulation within the cylinder may be removed when desired. The internal diameter of the piston cylinder or gun barrel 2 and the guide cylinder 4 is identical so as to form, when joined together, a continuous cylinder having the same internal diameter.

A piston I4 is mounted for movement within the cylinders 2 and 4 and extends from the rear end of the cylinder 4 forwardly to a point partially within the rear end of the cylinder 2. The forward end l5 of said piston is constructed and arranged so as to bear against the inside of said cylinder walls and, while being free to move back and forth within the cylinder walls, will not permit the clay or mud to pass into the back portion of the cylinder when said piston is moved forward against a column of clay within said cylinder 2. The rear end I6 of said piston also bears against the inside wall of said cylinder 4. The central portion of said piston, between the forward and rearward ends l5 and I6, respectively, is hollow and has a cylindrical wall connecting the front and rear ends of said piston. Openings are provided in the piston wall, one of which serves as a drain or clean-out opening and the other as a filling opening and suitable plugs I9 are positioned within said openings, so as to seal and prevent oil or grease which is contained within the hollow central portion of said piston from seeping out into the gun barrel. A threaded nut 20, fitted into the rear end iii of said piston I4, is secured thereon by means of bolts 2| so that said nut 20 cannot have independent movement in the piston but moves simultaneously therewith. The threaded nut 20 receives a threaded shaft 22 upon which it is adapted to rotate. The screw-shaft 22 is journaled in bearings 23 and 24 in said gear-housing 5. A

said shaft in either direction. A threaded portion of said screw-shaft 22 engages and passes through said nut and recedes in the hollow portion of said piston I4.

Securely mounted upon the end of said threaded shaft 22, within gear-housing 5, is a gear 26 adapted to mesh with a driving pinion 21 mounted, in any conventional manner, on a stub-shaft 28 which is journaled in bearings 29 and 30. Securely fastened on said stub-shaft 28, adjacent the pinion 21, is a gear 3| adapted to mesh with a driving-pinion 32 on a stub-shaft 33 which is mounted in suitable bearings 34 and 35 in the upper part of the gear-housing 5. The armature shaft 31 of the motor 6 is interconnected with the stub-shaft 33 by the coupling 36 which may be of either the rigid or flexible type.

The gear-housing 5, which completely encloses the gears and stub-shafts, is provided with an opening in the top side thereof through which oil or grease may be supplied to the interior of the gear-housing so that the gears are operated within a bath of oil or grease. A suitable plug 38 seals the opening to prevent the oil from seeping out.

Securely fastened in the rear end I8 of said piston M are pins 39 upon which is secured a pair of.guide-rollers 40, said guide-rollers being free to rotate on said pins. The pins and guiderollers 39 and 40, respectively, are so positioned and arranged on the rear end iii of said piston H as to permit the guide-bar l2 to move therebetween. It, therefore, becomes apparent that as the piston 14, due to rotation of the screwthreaded shaft 22, moves either in a forward or reverse direction, the guide-rollers 40 will bear on each side of the guide-bar I2 and as the piston i4 is advanced or retracted, said piston will follow the spiral path of the guide-bar l2 and thereby produce a rotary movement of said piston simultaneously with the longitudinal movement thereof.

In the form shown in Figures 5 and 6, the action is identical with that shown in Figure 2 except that in this modified form, the rotary movement of the cylinder I4 is accomplished in a diiferent manner. In Figure 5, the cylinder 14 has the front and rear supporting surfaces I5 and 5, respectively, as in Figure 2, but, instead of having the intermediate portion tapered as shown in Figure 2, the piston maintains a substantially cylindrical shape from the front end to the back end and is provided with a groove 4| which follows the contour of the piston half way around its length; or, if desired, may extend one full turn or any number of turns around the length of the piston. The cylinder 4, in this form of the invention, is provided with a pin 42 extending into the interior thereof for receiving a freely mounted roller 43 which is adapted to move within the groove 4| sothat, upon longitudinal movement of the piston, the roller 43 will follow the contour of the groove 4| and thereby cause a simultaneous rotary movement of the piston as it is being moved longitudinally within the cylinder. The driving mechanism is identical with that described in connection with the showing of Figure 2.

In the operation of the present invention, the cylinder 2 is filled with mud, clay or any other desired plastic material through the opening l after which the motor 6 is started to rotate the shaft 33. This produces a rotary movement of the screw-threaded shaft 22 through the gearhousing above described and, in so doing, causes the piston ll to advance in a forward direction within the cylinder walls and to eject, through the nozzle 3, the clay or other plastic material. In its forward movement, the piston is caused to simultaneously rotate as it is advanced, due to the rollers 38 and 0 cooperating with the guide-bar [2, to eject the clay or plastic material from the nozzle 3. Due to the fact that there is a double supporting surface at l5 and [6, respectively, for the piston, there can be no back flow of clay through the gun and a great pressure can be obtained at the discharge nozzle 3 with the result that it is possible to plug a tap-hole even while the blast is on in a blast-furnace. Furthermore, by having an elongated construction of the piston with its central portion hollow,

'an oil reservoir is provided within said piston so that the screw-threaded shaft always operates within a body of oil or grease. The piston having a combined simultaneous rotary and longitudinal movement minimizes power losses due to friction, and the rotary motion of the piston assists to free the piston should the barrel or cylinder become warped, as well as enables the piston to dislodge dry clay accumulating thereon.

While we have shown and described specific embodiments of the present invention, it will be understood that we do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of the invention, as defined by the following claims.

We claim:

1. In a mud gun, a cylinder having a discharge nozzle, means for discharging material therefrom including a plunger carrying longitudinally spaced annular bearing portions which slidingly engage the interior wall of said cylinder so as to thereby guide the plunger in its movements, a threaded shaft rotatably mounted by the cylinder and restrained against axial movement thereby, the plunger having a threaded portion for coaction with the shaft, and interengaging means between the plunger and cylinder including a spiral element whereby longitudinal movement imparted to the plunger by said threaded shaft is effective to turn the plunger about its longitudinal axis.

2. In a mud gun, a cylinder having a discharge nozzle, means for discharging material therefrom including a plunger carrying longitudinally spaced annular bearing portions which slidingly engage the interior wall of said cylinder so as to thereby guide the plunger in its movements, a threaded shaft rotatably mounted by the cylinder and restrained against axial movement thereby, a nut secured to the plunger for coaction with the shaft, and interengaging means between the plunger and cylinder including a spiralshaped bar secured to the cylinder and spaced rollers mounted on the plunger for coaction with said bar whereby the plunger is turned about its axis upon longitudinal movement thereof by said threaded shaft.

3. In a mud gun, a cylinder having a discharge nozzle, means for discharging material therefrom including an elongated plunger carrying longitudinally spaced annular bearing portions which slidingly engage the interior wall of said cylinder so as to thereby guide the plunger in its movements, a threaded shaft rotatably mounted by the cylinder and restrained against axial movement thereby, a nut secured to the plunger for coaction with the shaft, and interengaging means between the plunger and cylinder including a spiral shaped groove portion formed in the outer peripheral face of the plunger and a roller rotatably mounted by said cylinder for coaction with said grooved portion, whereby longitudinal movement imparted to the plunger by said threaded shaft will cause it to turn about its longitudinal axis.

4. In a mud gun, a mud-receiving cylinder provided with a discharge nozzle, an elongated plunger within said cylinder, a power-driven screw shaft rotatably mounted in the end of the cylinder remote from said nozzle and restrained by the cylinder from endwise movement, said plunger having a screw-threaded connection with said screw shaft and respective coacting means on the cylinder and the plunger and including a member progressing along a spiral line for causing the plunger during its reciprocations to rotate about its axis but at a rate of rotation slower than that of said screw shaft.

5. In a mud gun, a material-receiving cylinder having a discharge nozzle at one end thereof, a material-discharging plunger within said cylinder provided with longitudinally-spaced annular bearing portions connected by a reduced tubular portion, said bearing portions slidingly engaging the interior surface of said cylinder, a power-driven screw shaft rotatably mounted by the cylinder but restrained againstaxial movement relative thereto, said plunger having a screw-threaded portion engaging the screw shaft 1 and cooperating means between the inner wall of bearing portions connected by a reduced tubular portion, said bearing portions slidingly engaging the interior surface of the cylinder wall so as to be guided thereby, a reduced tubular portion connecting said bearing portions and adapted to retain a lubricant, a power-driven screw shaft, a nut coacting therewith secured to said plunger, the screw and nut being adapted to be lubricated by lubricant contained in said tubular portion, and means located wholly within the cylinder for causing the plunger during its reciprocation to rotate at a rate slower than that of said screw shaft.

7. In a mud gun, a plunger guide cylinder, a mud cylinder aligned with and forming a continuation of the plunger guide cylinder, a plunger having a bearing head at its forward end which is of a diameter to make a working fit with said cylinder walls, a guide portion at the rear end of the plunger, a tubular portion connecting said head and said guide portion, a screw shaft rotatably mounted by the cylinder and restrained against axial movement relative thereto, said plunger having a threaded portion cooperating with the screw shaft, and respective .coacting members on the plunger and cylinder, one of which progresses spirally around the plunger and is located entirely within the guide cylinder whereby, upon reciprocation of the plunger caused by rotation of the screw shaft, the plunger is turned about its axis at a rate slower than that at which the said screw turns.

8. In a mud gun, a receiving cylinder provided with a discharge nozzle at one end, an elongated plunger within said cylinder with its forward end snugly fitting said cylinder and its rear end slidingly engaging said cylinder and serving as a guide, said ends being connected by a tubular member of smaller diameter than said cylinder ends, a nut secured to the rear end of the plunger, a threaded shaft screwing into said nut, power means for rotating said screw shaft to reciprocate said plunger, and respective cooperating means supported partly by the cylinder and partly by the plunger and including a spiral element effective to cause the plunger to rotate in response to reciprocation thereof by said screw shaft but at a rate slower than the rate of rotation of the screw shaft.

ALFRED OSOLIN. JAY W. FERREE. 

